The present invention relates to a pressure relief valve for a packaging container.
Oxygen-sensitive goods, like, for example, coffee, are packaged in tightly sealed packaging containers in order to prevent spoilage due to oxygen. Because freshly roasted coffee does however produce carbon dioxide, increased pressure would then build up, which swells and eventually bursts the package. It is therefore known to provide the packaging container with pressure relief valves. A pressure relief valve, which comprises a base plate having a valve opening and a membrane over said valve opening, is known, for example, from the European Parliament patent publication EP 0 760 790 B1. The valve opening is thereby configured from two intersecting, annular openings. This pressure relief valve has basically proven to be successful, has however relatively large dimensions. For that reason, the pressure relief valves from prior art have to almost always be arranged on a front face. Front faces of this kind are however used as presentation surfaces and therefore undesirable restrictions result, for example with regard to the printing on the packaging, by mounting the pressure relief valve on the front face. The known pressure relief valve is furthermore relatively complex to produce because the base plate has to be partially wetted with adhesive and the membrane then affixed to the base plate. In so doing, a wrinkling can quickly occur, whereby the pressure relief valve is no longer leak-proof.